This is the battle walkthrough for the mission Taking Fort Merceus from Fire Emblem: Three Houses (FETH, FE3H). Read on to find out about map features, what enemies you will encounter, and tips for winning!

Previous Battle	Story Walkthrough	Next Battle
Chapter 19: Saving Derdriu	Chapter 20: The Impregnable Fortress	Chapter 21: Assault on Enbarr

Chapter 20 (Blue Lions) - Map and Overview

Victory Conditions
Defeat the enemy commander.
Defeat Conditions
Your character or Dimitri falls in battle.
# of Player Units	10
# of Enemies	38

Chapter 20 (Blue Lions) - Enemies

A	Imperial Soldier (Fortress Knight)	B	Imperial Soldier (Great Knight)
C	Imperial Soldier (Bishop)	D	Imperial Soldier (Dark Bishop)
E	Imperial Soldier (Warlock)	F	Imperial Soldier (Paladin)
G	Imperial Soldier (War Master)	H	Imperial Soldier (Warrior)
I	Imperial Soldier (Mortal Savant)	J	Imperial Soldier (Sniper)
K	Demonic Beast	L	Death Knight

Loot

Brave Axe

Caspar (or the war master on the east side of the map) drops a Brave Axe he has equipped upon defeat.

Chapter 20 (Blue Lions) - Chests

Extra Large Bullion - A

An Extra Large Bullion can be found on the northern chest marked as A on the image above.

Black Pearl - B

A Black Pearl can be found on the southern chest marked as B on the image above.

There are no keys available on this map so bring a unit with lockpick or bring chest keys to secure the treasures.

Chapter 20 (Blue Lions) - Map Features

## Tiles

Tiles	Description
Stairs	Difficult for cavalry to traverse
Rampart	Navigable only by fliers
Channel	Navigable only by fliers
Fire Orb	5 Mt, 15 Durability, 3-12 Rng, Can only be used by Magic Classes
Ballista	5 Mt, 15 Durability, 3-12 Rng, Requires Bow Skill of D or higher
Heal Tile+	1 Prt, 1 Res, +30% HP each turn for non-fliers

Ballistae and Fire Orbs

There are fire orbs and Ballistae scattered on the map. Navigate your units around taking these tiles to secure dominance in the battlefield.

Enemy Reinforcements

There's a small center fortress, with big aisles to either side of it, where reinforcements come from. The emplacements are elevated, but can be flown into to dispatch of quickly. The area is mazelike and hard to navigate.

Chapter 20 (Blue Lions) - Tips and Tricks

Taking out the Defenses

The ballistae and fire orbs are relatively unguarded, so sending a flyer in to take care of them could work, granted you defeat them once you swoop down.

Physical and Magic Sides

The blue area has more magic users while the yellow side has more damage dealers. Place your units accordingly.

Linhardt's side, the west side, mostly has mages while Caspars mostly has Cavaliers. Split your party accordingly so that your units susceptible to mages do not engage Linhardt's forces and vice versa.

Stopping Enemy Reinforcements

For every turn Caspar and Linhardt are alive, a Paladin and a Dark Bishop will come from the south entrance of their respective sides. Eliminate them and stop these units from spawning.

Using Ballistae against Caspar and Linhardt

If you take the center early and man the ballistae, Caspar, Linhardt and their retinue are in range of it and can be attacked by them.

Take out the Magic Orb Early

If you have a flier, putting them on your right flank can have them reach the eastern magical orb in turn one if they're strong enough to beat the Dark Bishop in one hit. Recommend using a Pegasus Knight, as they are strong versus mages.

Fire Emblem: Three Houses - Related Links

Part 2 - Azure Moon Battle Walkthroughs

Part 2 - Azure Moon
Chapter 13: Hunting at Daybreak	Chapter 14: Protecting Garreg Mach	Chapter 15: Ambush at Ailell
Chapter 16: The Great Bridge Coup	Chapter 17: To War at Gronder	Chapter 18: Reclaiming the Capital
Chapter 19: Saving Derdriu	Chapter 20: Taking Fort Merceus	Chapter 21: Assault on Enbarr
Chapter 22: Clash at the Imperial Capital